Apparatus for quenching molten coatings

ABSTRACT

A wire passing upwardly after having passed through a molten metal coating bath is contacted with a moving stream of water jetting upwardly through the atmosphere at an angle. The stream of water and the moving wire meet just at the apex of the stream where the energy of movement of the water is least. The cooling stream of water thus causes a minimum disturbance of the still molten coating on the wire.

United States Patent 1191 Padjen et a1.

[ Dec. 10, 1974 1 APPARATUS FOR QUENCHING MOLTEN 2,732,319 1/1956 Cree118/69 x COATINGS 2,833,672 5/1958 Laubscher et a1. 118/69 x 3,112,22611/1963 St. Jean 118/69 X Inventors: George i J s p eg 3,428,023 2/1969Cox et a1. 118/69 x both of Bethlehem, Pa. 3,554,513 1/1971 Chance 216/3R [7 gnee e em steel o por 3,727,895 4/1973 Wondergem 1. 117/1194 XBethlehem, Pa.

Primary Examiner-Morris Kaplan 22 F F 197 1 eh 3 Attorney, Agent, orFirm-Joseph J. OKeefe; Charles [21] App]. No.: 336,653 A. WilkinsonRelated US. Application Data [62] Division of Ser. No. 213,143, Dec. 28,1971, Pat. No.

3,743,535. ABSTRACT [52] US. Cl. 266/3 R 118/69 A wire passing upwardlyafter having Passed through a 51 1111. C1 c2111 1/64 when metal matingbath is waded with a "Wing [58]' Field of Search.... ll8/63,'67, 69, 68,DIG. 18, Steam 0f water letting Pwardly, thmugh the 118 /DIG 19 266/3 R4 S 6 sphere at an angle. The stream of water and the mov- 117/1 19.4.164/89 5 134/2) ing wire meet just at the apex of the stream where theenergy of movement of the water is least. The cooling stream of waterthus causes a minimum disturbance of [56] References Cited the stillmolten coating on the wire.

v UNITED STATES PATENTS 6 3 Drawing Figures 2,166,249 7/1939 Herman118/420 X 3 1 4'7 7/ 73 3 i 4/ i 5 T BACKGROUND OF THE INVENTION Thepresent invention relates generally to apparatus for quenching of coatedwire and other linear material and more particularly to the quenchingwith a fluid cooling medium of a molten metallic coating on a movingcontinuously coated wire or the like.

It is frequently desirable to cool or quench a moving length of linearmaterial such as wire or narrow strip passing upwardly out of a moltenbath of coating metal such as molten zinc, aluminum or copper. Promptquenching of the linear material is frequently important in order toretard the development of an interfacial alloy layer between the coatingmetal and the base metal or to solidify the coating metal promptly sothat it can be contacted with a guide sheave or the like either tochange the direction of the linear material or to damp vibrations in thewire.

If linear material is contacted with any sort of guide prior tosubstantial solidification ofa recently applied molten coating upon thesurface, the still molten coating would be marred by the contact, evenwhere the guide only gently contacts, or kisses, the linear material. Onthe other hand a molten coating metal deposited upon a moving wire orstrip will frequently take a significant period to solidify in ambientshop conditions and if the linear material is moving at a fair speed itcan travel long distances before solidification occurs. This longdistance is usually arranged to be in a vertical direction upwardly fromthe coating pot so that the molten metal will not be differentiallyaffected by gravity. The long unsupported length of linear material may,however, be subject to rather severe vibration which frequently willcause lumpy and/or eccentric coatings.

Various quenching means have been used to quench a still molten coatingwithout marring the surface of the coating. In general these quenchingdevices have involved either blasts of a gas such as air, line mists ofa fluid cooling medium such as water, fine sprays of water or the likeor in some cases quenching in a tank of cooling fluid. In general eachof these prior devices has suffered from some serious drawbacks eitherbecause the cooling action afforded was insufficient or the physicaldisturbance of the coating by the quenching means was too great.

SUMMARY OF THE INVENTION The aforesaid difficulties of the prior art inquenching still molten coatings on moving linear material have now beenobviated by the present invention. In accordance with the presentinvention a coated wire, narrow strip or other linear material passingfrom a molten coating bath or other means for applying a molten coatingis quenched by contacting the coating with a moving stream or streams ofan .upwardly directed cooling fluid, or liquid, at the apex of theupward movement of such stream or streams. The stream or-streams ofcooling fluid are generally in the form ofa fountain of fluid similar tothe stream in a drinking fountain. The upwardly directed component ofmotion of the stream of liquid is just barely exhausted at the apex ofmovement of the said fountain type stream so that there is at this pointan absolute minimum of movement in the stream of liquid to disturb thestill molten coating on the wire while at the same time the coolingliquid contacting the coating is continuously renewed at a rapid ratewith fresh cooling liquid to most efficiently quench the coating. Sincethe upward component of motion of the stream is then exhausted, the onlymovement of the cooling liquid at the apex is whatever horizontalcomponent of movement the liquid has. This horizontal component can bemade as small as desired depending upon where the exhausted liquid isdesired to impinge as it descends from the apex of its trajectory andthe resulting contact of the cooling fluid with the object being cooledand the coating on it can be adjusted to be only the barest touch whilestill renewing large quantities of cooling liquid next to the coatedsurface. The moving liquid thus achieves what has been termed laminarflow cooling but with only very gentle contact on the piece beingquenched.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic representation ofa portion of a coating line incorporating the quench arrangement of thepresent invention.

FIG. 2 is an enlarged sectional view of the quenching device of theinvention.

FIG. 3 is a plan view of FIG. 2 at 3-3.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 a wire 11 passes froma pretreatment apparatus 13 which may frequently be a preheating furnacebut which may also be a cleaning apparatus or flux applying apparatus.As the wire 11 leaves the pretreatment apparatus 13 it passes over guidesheave 15 which directs the wire downwardly into a molten metal coatingbath 17 containing a molten coating metal such as aluminum, zinc orcopper. The molten metal comprising bath 17 is contained in a moltenmetal coating pot l9. Wire 11 passes downwardly under sinker roll 21submerged under the surface of the bath l7 and then upwardly out of themolten bath 17 to dancer roll 23 where the wire 11 changes direction andpasses downwardly under guide sheave 25 which directs the wire away fromthe coating pot 19 to some other treatment or coiling operation, notshown. The distance from the surface of the molten bath 17 to the dancerroll 23 is frequently substantial to allow time for the molten coatingto solidify before contacting the roll 23. In order to cause acceleratedsolidification of the molten coating on the wire 11 after it leaves thebath 17, so that the wire may be contacted with a vibration dampingcontact roll 27 and also to decrease the growth of an interfacial alloylayer between the coating metal and the underlying base metal of thewire if such an interfacial alloy tends to form between the base metaland the particular coating metal the wire 11 first passes through alight forced air stream from dual nozzles 29 and 31 connected by header33 to a source of compressed air, not shown. A valve 35 in the header 33may be used to regulate the flow of air from nozzles 29 and 31 so thatthe forced air flow is sufficient to just cool the surface of thecoating. Such air flow may be adequate to place a very thin solidifiedshell of coating metal over the surface but should not be sufficient tootherwise disturb the surface. The wire 11 next immediately passes to afountain type quench apparatus 37 where the surface of the coating isquickly cooled below the solidification point and the entire wire issubjected to accelerated cooling by a laminar flow of a cooling liquidsuch as water past and around the surface of the wire.

The quench apparatus 37 is constructed as shown best in FIGS. 2 and 3 sothat a series of discrete streams or jets of water 53 and 55 areprojected upwardly at an angle calculated to intersect with the upwardpath of the wire or wires 11 just as the upward movement of the saidstreams or jets of coolant has reached its highest point or elevation.The stream of flowing water thus has a bare minimum of motion when itintersects the wire 11 and only a very gentle contact with the surfaceof the coating takes place. The coolant water, however, is still quicklyremoved, or moved past the wire, so that a good laminar flow typecooling of the molten metal coating on the wire is attained.

In the quench apparatus 37 cooling water from an external source, notshown, enters the apparatus from a main header 39 regulated by a valve41. From the main header 39 the water enters two vertically disposeddescending headers 43 and 45 and a cross over-or connecting header 47.Spaced at intervals along the descending headers 43 and 45 are upwardlyinclined cooling nozzles 49 and 51, respectively, positioned at anglessuch that a stream or jet of water 53 and 55 issuing from each of thenozzles 49 and 51 respectively intersects the wire 11 at the apex of thestream and then falls in a descending arc downwardly into sumps 57 and59 in the bottom of the casing 61 of the quench apparatus 37. Drains 63and 65 connect with a main 67 and serve to remove the water from thevarious streams from the sumps 57 and 59.

As seen in FIG. 2 the two sets of nozzles 49 and 51 are positioned upontheir respective descending headers 43 and so that the streams orfountains of water 53 and 55 issuing from them intersect the wire 11 atdifferent levels to prevent the splashing which would ,ant. It will beunderstood that in FIGS. I and 2 additional wires 11 passing through theapparatus may be hidden behind the wire 11 visible in the respectiveviews. In FIG. 3 duplicate numbers are used to identify duplicateheaders and nozzles used to apply cooling streams to additional wires11.

Since practically all of the cooling water from each of the nozzles 49and 51 passes freely around and past the wire 11 and continues in moreor less discrete streams into the sumps 57 and 59, it will be seen thatvery little water is left over to run down the wire or wires 11 into thecoating pot 19. Likewise there is very little splashing caused by thewire or wires passing through the apex of each cooling stream of water.Any water which clings to the wire is drawn upwardly and away with themoving wires and is also usually rapidly evaporated from the stillrelatively hot surface of the wire. The fountain type quench of theinvention is,

therefore, particularly suitable for placement directly over a moltencoating bath where any substantial dripping or splashing of water orother cooling liquid upon the bath would be intolerable. This is animportant advantage since it is usually advantageous to pass a wire orother elongated material vertically up from a molten bath until theouter coating solidifies in order that the molten coating will not bedifferentially affected by gravity. The quench apparatus of the instantinvention can be placed on the vertical run of the linear material fromthe bath without any significant moisture escaping downwardly from theapparatus even though there are no seals around the wires. (Seals mightdamage the still molten coating.) A relatively large entrance orifice 69may thus be provided in the bottom of the apparatus equal or evengreater in size than the exit orifice 71 for the linear materialpositioned in the top 73 of the apparatus.

The use of the initial gentle blast or flow of cooling air directed uponthe linear material fromnozzles 29 and 31, while very desirable prior topassage of the wire through the fountain type quench of the invention,is by no means necessary for use with the quench if the air is notdesired. The cooling air stream from the air nozzles 29 and 31 will tendto form a very thin skin or incipient skin of solidified coatingmaterial upon the surface of the wire which skin, when the wire passesthrough the fountain type quench, is just sufficient to prevent anydisturbance at all of the surface of the still unsolidified coating asit passes through the apex of the stream of coolant in the fountainquench apparatus. The combined use of the forced air cooling followedimmediately by the fountain type quench of the invention is particularlyeffective and desirable if there is a fair component of horizontalmovement of the coolant streams at the apex of said streams. On theother hand, however, it is by no means necessary to use the initialforced air cooling prior to quenching, particularly if the angle of thestreams of coolant is arranged so that the horizontal component ofmotion is minimal at the apex of said streams, or if a very minor ornegligible disturbance of the coating surface is not regarded asseriously detrimental.

It is likewise not always necessary to use the vibration damping contactroll 27 with the quench apparatus 37. The dancer roll 23 can instead bemoved down closer to the coating pot 19 to replace the damping roll 27if vibration damping is desired, or if vibration is not deemedimportant, and quenching is accomplished in the particular operationmerely to decrease interface alloy formation, the dancer roll 23 may beleft in the same position. The use of the additional vibration damperroll 27, which may be adjusted by suitable biasing mechanism to justkiss" the wire after the quench, is particularly effective anddesirable, however.

We claim:

1. Apparatus for cooling moving molten material coated wire-likematerial comprising:

a. a cooling chamber defining a vertical path for said wire-likematerial,

b. means to form at least one liquid cooling jet within said coolingchamber, said means being arranged to direct said cooling jet as adiscrete free stream of liquid upwardly at an angle other thanvertically with the path of said stream intersecting the path of saidwire-like material at the apex of the path of said discrete stream ofcooling liquid where substantially all vertical components of themovement of said stream is dissipated,

c. said means for forming said liquid cooling jet comprising headermeans for conveying cooling liquid from an external source into thevicinity of the cooling chamber and nozzle means connected to the headermeans and inclined upwardly at an angle such that a stream of coolingliquid ejected from the nozzle means is projected upwardly at an anglesuch that the stream of coolant intersects the path of the wire-likematerial at the apex of the stream of coolant just prior to beginning tofall in a descending arc downwardly from the said apex, and

d. means to collect said descending coolant.

2. Apparatus for cooling wire-like material according to claim 1 whereinthe liquid cooling jet is comprised of a single undivided stream ofliquid adapted to cool the wire-like material with a gentle laminar flowof liq- 6. Apparatus for cooling moving wire-like material according toclaim 5 wherein the cooling chamber of (a) is followed by a vibrationdamping means physically contacting the wire-like material adjacent tosaid chamber.

1. Apparatus for cooling moving molten material coated wire-likematerial comprising: a. a cooling chamber defining a vertical path forsaid wire-like material, b. means to form at least one liquid coolingjet within said cooling chamber, said means being arranged to directsaid cooling jet as a discrete free stream of liquid upwardly at anangle other than vertically with the path of said stream intersectingthe path of said wire-like material at the apex of the path of saiddiscrete stream of cooling liquid where substantially all verticalcomponents of the movement of said stream is dissipated, c. said meansfor forming said liquid cooling jet comprising header means forconveying cooling liquid from an external source into the vicinity ofthe cooling chamber and nozzle means connected to the header means andinclined upwardly at an angle such that a stream of cooling liquidejected from the nozzle means is projected upwardly at an angle suchthat the stream of coolant intersects the path of the wire-like materialat the apex of the stream of coolant just prior to beginning to fall ina descending arc downwardly from the said apex, and d. means to collectsaid descending coolant.
 2. Apparatus for cooling wire-like materialaccording to claim 1 wherein the liquid cooling jet is comprised of asingle undivided stream of liquid adapted to cool the wire-like materialwith a gentle laminar flow of liquid past the surface of the wire-likematerial.
 3. Apparatus for cooling wire-like material according to claim2 wherein there are means establishing a multiplicity of liquid coolingjets along the line of travel of the wire-like material through saidchamber.
 4. Apparatus for cooling moving wire-like material according toclaim 1 wherein the liquid cooling jet is comprisEd of water. 5.Apparatus for cooling moving wire-like material according to claim 4wherein the cooling chamber of (a) is preceded by a forced air coolingmeans impinging streams of relatively cool air upon said linearmaterial.
 6. Apparatus for cooling moving wire-like material accordingto claim 5 wherein the cooling chamber of (a) is followed by a vibrationdamping means physically contacting the wire-like material adjacent tosaid chamber.